corrected retention volume in gas chromatography

The corrected retention volume, $V R 0$ , is given by

$V R 0 = j V R$

where $j$ is the pressure gradient correction factor for a homogeneously filled column of constant diameter and $V R$ is the retention volume. This quantity is of limited use because it is influenced by the volumes of the sample injector and detector, as well as the interstitial volume of the column.

Source:

Orange Book, p. 104